package io.zy.common.utils;

import com.alibaba.druid.util.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.http.HttpServletRequest;

/**
 * IP地址
 * 
 * @author chenshun
 * @email sunlightcs@gmail.com
 * @date 2017年3月8日 下午12:57:02
 */
public class IPUtils {
	private static Logger logger = LoggerFactory.getLogger(IPUtils.class);

	/**
	 * 获取IP地址
	 * 
	 * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
	 * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
	 */
	public static String getIpAddr(HttpServletRequest request) {
		String ip = null;
		try {
			ip = request.getHeader("x-forwarded-for");
			if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
				ip = request.getHeader("X-Real-IP");
				if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
					ip = request.getHeader("Proxy-Client-IP");
					if (StringUtils.isEmpty(ip) || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
						ip = request.getHeader("WL-Proxy-Client-IP");
						if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
							ip = request.getHeader("HTTP_CLIENT_IP");
							if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
								ip = request.getHeader("HTTP_X_FORWARDED_FOR");
								if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
									ip = request.getRemoteAddr();
								}
							}
						}
					}
				}
			}
		} catch (Exception e) {
			logger.error("IPUtils ERROR ", e);
		}
		return ip;
	}
}
